Remotely adjustable gastric banding device

ABSTRACT

A remotely controllable gastric banding device ( 10 ) for placement around the stomach of a patient for the treatment of obesity. The device ( 10 ) comprises a gastric band ( 10 ) having an inflatable chamber ( 16 ) for adjusting the inner circumference of the band ( 10 ), a pressurized reservoir ( 20 ) with a valve ( 31 ) for providing fluid to inflate the inflation chamber ( 16 ), a valve ( 32 ) for releasing fluid from the inflatable chamber ( 16 ), and a controller ( 41 ) for controlling the valves ( 31, 32 ). The controller ( 41 ) is remotely controllable from outside the patient.

RELATED APPLICATION(S)

The present application is a continuation of U.S. patent applicationSer. No. 10/524,864, filed Jun. 23, 2005, now U.S. Pat. No. 7,338,433,issued Mar. 4, 2008, which was a National Stage Entry of PCT/US02/25654,filed Aug. 13, 2002.

FIELD OF THE INVENTION

The present invention relates generally to an apparatus for remotelyadjusting the volume in the inflatable portion of a surgically implantedgastric band encircling the stomach. A method for treating morbidobesity utilizing a remotely adjustable gastric banding device is alsodisclosed.

BACKGROUND OF THE INVENTION

A belt-like gastric band for encircling the stomach to control morbidobesity is disclosed by Vincent in U.S. Pat. No. 5,601,604, incorporatedherein by reference. The band comprises a belt that can be passed aroundthe stomach and locked into an encircling position in order to create astoma opening within the stomach. An adjustable portion of the bandcomprises an inflatable member which permits fine adjustment of thestoma opening after the stoma is created by locking the band in place.

The gastric banding procedure may involve placement of a calibratingapparatus in the stomach to position the stoma and size the pouchcreated above the stoma. The gastric band is fastened in position aboutthe stomach to prevent slippage, usually by gastro-gastric sutures.

The stoma opening may be adjusted by injecting or withdrawing a fluidinto or from an inflatable member, which is preferably coextensive witha portion of the inner stomach-contacting surface of the band. The meansfor injecting the fluid into the inflatable member usually comprises afill port located beneath the skin that can be accessed extracorporeallyby transdermal injection. Thus, following implantation, the gastric bandcan be adjusted to enlarge or reduce the stoma as required.

A potential disadvantage of prior art gastric bands is the difficulty infinely adjusting the stoma created by the implanted band. For example,the fill port located beneath the skin can be difficult to locateprecisely. In addition, the fill procedure requires an invasivetransdermal injection to adjust the band. Hence, repeated adjustmentsmay be painful or worrisome to the patient. Moreover, exposure to x-raysmay be required to facilitate location of the port. It would thereforebe desirable to provide a band having an inflatable member that can beeasily, precisely, and readily adjusted remotely, without the need toundergo an invasive procedure or radiographic exposure.

To address this problem, several prior art remote control gastricbanding devices have been proposed. Klaiber et al. (U.S. Pat. No.5,938,669) discloses a radio controlled gastric band adjusted by meansof an electric pump and a balancing reservoir. Forsell (U.S. Pat. No.6,210,347) discloses a remotely controlled and powered gastric bandadjusted by a motorized mechanical or hydraulic means. Each of theseproposed devices operates by pumping fluid to or from the gastric band.Unfortunately, because of their energy requirements, these devices poseproblems for practical use. These devices are also not suitable for usewith existing gastric banding systems, such as that disclosed byVincent.

Recent developments in implantable drug delivery devices have shown thatsmall, reliable, and energy-efficient implantable devices are feasible.

Drug delivery devices currently exist in which drugs are administeredperiodically or continuously to a patient having an implanted device byapplying pressure from a pressurized reservoir and opening an outletvalve to allow a pressure differential to cause a flow of the drug. Forexample, Malamud et al. (U.S. Pat. No. 5,928,195) discloses a remotelycontrolled drug delivery device suitable for implantation in a bodycavity. A pressurized gas chamber presses upon a drug storage chamberthereby administering a dose of the drug when a valve is remotelyopened.

Similarly, Arzbaecher (U.S. Pat. No. 5,607,418) discloses an implantabledrug apparatus having nested deformable chambers with the outer chamberbeing pressurized. The pressure from the outer pressurized chamberforces the drug from a reservoir chamber into an inner dispensingchamber. A remotely controlled valve is used to administer a dose of thedrug from the dispensing chamber.

Further, Haller et al. (U.S. Pat. No. 6,203,523) discloses animplantable drug infusion device having a flow regulating mechanism thatpermits the flow rate to be independent of reservoir pressure. Some ofthe tradeoffs between “passive” (pressurized reservoir-based) devicesand “active” (pump-based) devices are discussed in Haller, as follows:

Active drug or programmable infusion devices feature a pump or ametering system to deliver the drug into the patient's system. Anexample of such an active drug infusion device currently available isthe Medtronic SynchroMed™ programmable pump. Such pumps typicallyinclude a drug reservoir, a peristaltic pump to pump out the drug fromthe reservoir, and a catheter port to transport the pumped out drug fromthe reservoir via the pump to a patient's anatomy. Such devices alsotypically include a battery to power the pump as well as an electronicmodule to control the flow rate of the pump. The Medtronic SynchroMed™pump further includes an antenna to permit the remote programming of thepump. Needless to say, in view of these various components, the cost aswell as the size of active drug infusion devices is greater thandesired.

Passive drug infusion devices, in contrast, do not feature a pump, butrather rely upon a pressurized drug reservoir to deliver the drug. Thussuch devices tend to be both smaller as well as cheaper as compared toactive devices. An example of such a device includes the MedtronicIsoMed™. This device delivers the drug into the patient through theforce provided by a pressurized reservoir. In particular, this reservoiris pressurized with a drug to between 20 to 40 psi (1.3 to 2.5 bar) andis used to deliver the drug into the patient's system. Typically theflow path of the drug from the reservoir to the patient includes a flowrestrictor, which permits a constant flow rate. The flow rate, however,is only constant, if the pressure difference between reservoir andpatient does not change. Factors that could impact this pressuredifference include temperature, pressure-volume dependence of reservoirand altitude, among others. The selected pressure for the reservoir isthus typically quite high, so that absolute pressure changes only causesmall and acceptable errors in flow rate. This also requires, however,the drug to be injected into the reservoir using still higher pressure.This is often a very difficult to achieve using a hand operated syringe.

The foregoing demonstrates a need for a practical, accurate and easymeans of remotely adjusting an implanted gastric band.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide apractical, accurate and efficient means for remotely adjusting animplanted gastric band.

It is another an object of the present invention to remotely adjust animplanted gastric band having an inflatable member.

It is yet another object of the invention to provide a remote controlmeans suitable for use with existing gastric banding devices andtechnology.

Still another an object of the present invention is to minimize devicecomplexity for an implanted remotely adjustable gastric banding deviceto ensure maximum device longevity/durability, in light of the fact thatrepair would require additional surgery.

Various other objects, advantages and features of the present inventionwill become readily apparent from the ensuing detailed description andthe novel features will be particularly pointed out in the appendedclaims.

SUMMARY OF THE INVENTION

The present invention applies recent developments in implantable drugdelivery device technology to the field of gastric banding.

A preferred embodiment of the invention provides a gastric bandingdevice for treatment of morbid obesity. The device has a gastric bandsuited for laparoscopic placement around the stomach of a patient toform an adjustable stoma opening. The gastric band has an inflatablechamber for adjusting the inner circumference of the band. Theinflatable chamber is preferably substantially coextensive with an innerstomach-facing surface of the gastric band. The inflatable member doesnot wrinkle or fold when adjusted, thereby presenting a substantiallysmooth contour along the inner circumference. A fluid-filled pressurizedreservoir provides a source of fluid to inflate the inflation chamber ofthe gastric band. First and second valves control the flow between thepressurized reservoir, the inflatable chamber, and an unpressurized ornegatively pressurized outlet. A controller is used to control thevalves, thereby regulating the volume change in the inflatable chamberto adjust the inner circumference of the band. The controller isremotely controllable from outside of the patient.

Other aspects of the invention include a remote control for remotelytransmitting control signals to the controller, a receiver for receivingcontrol signals from the remote control, and a power source forproviding power to the controller and the valves. The power source maybe an induction coil. The power source may also be a battery orcapacitor charged by a piezoelectric device which converts body motioninto electrical energy.

In a method according to the invention, a remotely adjustable gastricbanding system may be use for the treatment of obesity. The methodcomprises the steps of implanting a gastric band, preferablylaparoscopically, around the stomach of the patient to create a stoma;remotely transmitting control signals from outside of the patient to acontroller of the implanted gastric banding device; and actuating afirst valve, between a pressurized reservoir and an inflatable chamber,and/or a second valve, between the inflatable chamber and an outlet, onthe basis of the control signals received by the controller to increaseor decrease the fluid volume in the inflatable chamber, therebyadjusting the inner circumference of the band to adjust the stoma.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawings in which:

FIG. 1 is a perspective view of a laparoscopically implantable gastricband, which may be used in the present invention, fastened in anencircling position and partially inflated;

FIG. 2 is a side view of the gastric band shown in FIG. 1; and

FIG. 3 is a schematic diagram showing a remotely controlled fluiddistribution system for a gastric band according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention combines the implantable drug delivery devicetechnology discussed above with gastric banding technology. Thepreferred embodiments of the apparatus and method according to thepresent invention will be described with reference to the accompanyingdrawings.

Referring to FIG. 1, a gastric band for use with the present inventionis disclosed in Vincent (U.S. Pat. No. 5,601,604). This compatiblegastric band, indicated as reference numeral 10, has a body portion 11with an inner stomach-facing surface 15. The body portion 11 has a headend 12 and a tail end or “belt” 13. A fill tube 14, which is generally atube having a single lumen coextensive therewith, is in fluidcommunication with an inflatable chamber 16 on the inner surface 15 ofthe band body 11. Preferably, the inflatable portion 16 is substantiallycoextensive with the inner surface 15 of the body portion 11. Thecentral lumen of the fill tube 14 is in fluid communication withinflatable chamber 16. The head end 12 of the body portion 11 has a“buckle” 19 through which the tail end of “belt” 13 is inserted andlocked in place in use. Head end 12 may be provided with a pull tab 18for use in locking the band in place about the stomach.

In use, the gastric band is placed in an encircling position around thestomach and locked in place as shown in FIG. 2. (In FIG. 2, the stomachis omitted for clarity.) This is accomplished by introducing the gastricband 10 through a laparoscopic cannula (not shown) in a patient'sabdominal cavity. Laparoscopic placement consists of blunt dissectionbelow the gastro-esophageal junction followed by placement of the band.The end of the fill tube 14 is passed through the dissected path aroundthe upper stomach, and the tail end or belt 13 is passed through buckle19, so that the belt and buckle lock in place. A laparoscopic closuretool, such as that disclosed by Coe and Vincent in U.S. Pat. No.5,658,298, incorporated herein by reference, may be used. Hence, withthe gastric band affixed in an encircling position around the stomach, anew stoma (opening) is created within the stomach. After the band issecured in position, the size of the stoma may be adjusted by addingfluid to or withdrawing fluid from the inflatable member 16 to bring thestoma opening to the desired size. The inflatable member or chamber 16is preferably coextensive with the inner stomach-facing surface 15 ofthe band between the head end 12 and the tail end 13. The interior ofthe adjustable chamber 16 is in fluid communication with a fluidreservoir (not shown) by means of the central lumen of the fill tube 14,as with prior art adjustable gastric bands. The inflatable member 16 isgradually inflated or deflated with saline or other biologicallycompatible fluid via the fluid reservoir such that the inflatable member16 presses on and constricts the stomach wall or other tissue underlyingthe band. This results in the decrease or increase of the size of thestomach opening directly inside the encircling band.

FIG. 3 is a schematic diagram depicting a remotely adjustable gastricband 100 constructed in accordance with the present invention. In FIG.3, the pressure in the inflatable member 16 of the remote gastricbanding system 100 is represented by the band inflation pressure P2.Pressure P2 is regulated by an inlet valve 31 and an outlet valve 32.Pressurized reservoir 20, having a pressure P1, is connected to theinflatable chamber 16 through inlet valve 31 and tube 21, whichcorresponds to fill tube 14 in FIG. 2. Pressurized reservoir 20 isanalogous to the pressurized reservoirs discussed above in relation toimplantable drug delivery devices. This reservoir may be connected tothe fill tube 21 as shown, or it may be incorporated into the body 11 ofthe band itself, e.g. on the outer surface, opposite the innerstomach-facing surface 15, and communicate directly with inflatablechamber 16 though inlet valve 21. Inflatable member 16 is also connectedto outlet 23, having a pressure P3, through tube 22 and valve 32. Outlet23 may be either a separate waste reservoir as shown in FIG. 3 or theperitoneal cavity of the patient's body. When outlet 23 is a wastereservoir, P3 may be negative. Where pressure outlet 23 is the patient'speritoneal cavity, P3 will be at ambient pressure within the body.

In the present invention, the pressure relationship between reservoir20, inflatable member 16 and outlet 23 is initially represented by theformula P1>P2>P3. Hence, valve 31 may be used to increase the pressureP2 up to a maximum pressure of P2=P1, thereby inflating inflatablemember 16. Similarly, valve 32 may be used to decrease the pressure P2down to a minimum of P2=P3, thereby deflating inflatable member 16.Thus, by actuating valves 31 and 32, the fluid volume in the inflatablemember 16 may be regulated, thereby adjusting the size of the stomaformed by the gastric band.

In the present invention, valves 31 and 32 are controlled by acontroller 41. The valves are preferably controlled in accordance withexternally transmitted signals (not shown) received by a receiver 42 butmay ultimately be controlled by any control system, including internal,mechanical, wired, or the like. The signals are preferably radiofrequency (RF) signals transmitted by a remote control device 40 locatedexternal to the implanted gastric banding system. Power may be suppliedto the receiver, the controller, and/or the valves either from animplanted power source 43 or from an induction coil 43 that receivespower from a concentric coil external to the body, as described forinstance for hearing aids in Baumann et al. (U.S. Pat. No. 5,279,292),which is hereby incorporated by reference.

The entirety of the remote gastric banding system 100 shown in FIG. 3may be laparoscopically implanted in the patient. Subsequent adjustmentof the band can be simply, quickly, and painlessly performed using aremote control device to remotely inflate/deflate the inflatable portion16 of the band. The entire system 100 may be removed from the patient ifnecessary. No permanent anatomical changes should be anticipated.

The remote control device 40 can be in the form of a typical televisionremote control, a personal computer interfaced device, or any otherformat. A unique identification code may be assigned to each remotelyadjustable gastric band, so that access to and control of the device isrestricted. This code may be a PIN code and may also act to preventaccidental adjustment of the band.

The system may be pressurized using a saline solution, or any otherbiocompatible fluid. If desired, a concentrated saline solution may beused as the inflation medium, thereby allowing water from the patient'sbody to diffuse into the inflatable member 16 over time and furtherinflate the band. After repeated adjustments the reservoir 20 may berefilled through an access port (not shown) or replaced altogether. As abackup and safety measure, the system may also allow forinflation/deflation of inflatable member 16 by transdermal injectionthrough a fill port (not shown) as in prior art gastric banding devices.

Because this system uses a pressurized reservoir rather than amechanical pressurization means (i.e. a pump or screw), the presentsystem is more energy-efficient than those disclosed in the existingremote-controlled adjustable gastric band systems of Klaiber or Forsell(U.S. Pat. Nos. 5,938,669 and 6,210,347). Power is only required whenoperating the valves 31 and/or 32, and then only for relatively shorttime intervals.

Alternative embodiments of the present invention may include means formeasuring fluid flow through the valves 31 and/or 32, such as a massflowmeter, to ensure accuracy in adjusting the stoma when inflatablemember 16 is inflated or deflated. Also, the controller 41 may bepositioned external to the body. An alternate gastric band design mightalso be used, provided that the inflation medium remains a fluid.

A further embodiment of the present invention is a method of treatingobesity using the remotely adjustable gastric banding system disclosedherein. The method includes implanting a gastric band, preferablylaparoscopically, around the stomach of the patient to create a stoma;remotely transmitting control signals from outside of the patient tocontroller 41 of the gastric banding device inside of the patient; andopening and closing valve 31, between pressurized reservoir 20 andinflatable chamber 16, and/or valve 32, between the inflatable chamberand outlet 23, on the basis of the control signals received bycontroller 23 to increase or decrease the pressure in the inflatablechamber, thereby adjusting the inner circumference of the band to adjustthe stoma size.

Although the invention has been particularly shown and described withreference to certain preferred embodiments, it will be readilyappreciated by those of ordinary skill in the art that various changesand modifications may be made therein, without departing from the spiritand scope of the invention. It is intended that the claims beinterpreted as including the foregoing as well as various other suchchanges and modifications.

1. A passively pressurized inflatable gastric banding apparatus fortreatment of obesity in a patient, comprising: a gastric band suitablefor laparoscopic placement around the stomach of the patient to create astoma opening, the gastric band having an inflatable chamber defining aninner circumference of the band, the pressure within the inflatablechamber being denoted P2; a pressurized fluid reservoir connected toprovide fluid to inflate the inflation chamber, the pressurized fluidreservoir having a pressure P1; an inlet valve between the pressurizedfluid reservoir and the inflatable chamber; an outlet that is not thepressurized fluid reservoir having a pressure P3; an outlet valvebetween the inflatable chamber and the outlet; and a controller foractuating the inlet valve and passively increasing the fluid volume inthe inflatable chamber when P1>P2, or actuating the outlet valve andpassively decreasing the fluid volume in the inflatable chamber whenP2>P3, thereby adjusting the inner circumference of the band.
 2. Thegastric banding apparatus of claim 1, wherein the controller includes areceiver and is remotely controllable from outside of the patient, andfurther comprising a remote control for remotely transmitting controlsignals to the controller.
 3. The gastric banding apparatus of claim 2,wherein the receiver is an RF receiver and the controller actuates theinlet and outlet valves in response to the received RF signals.
 4. Thegastric banding apparatus of claim 1, further comprising a power sourcefor providing power to the controller, the first valve, and the secondvalve.
 5. The gastric banding apparatus of claim 4, wherein the powersource is selected from the group consisting of: an induction coil, abattery, a capacitor, and a piezo-electrically charged capacitor.
 6. Thegastric banding apparatus of claim 1, wherein the outlet is adapted tobe in fluid communication with the peritoneal cavity of the patient. 7.The gastric banding apparatus of claim 1, wherein the outlet is a wastereservoir.
 8. The gastric banding apparatus of claim 7, wherein thewaste reservoir is negatively pressurized.
 9. The gastric bandingapparatus of claim 1, wherein the inflatable chamber is substantiallycoextensive with an inner stomach-facing surface of the gastric band toform a circular adjustable stoma opening.
 10. The gastric bandingapparatus of claim 1, further including a fill tube connected to theinflatable chamber and a fill port on the end of the fill tube suitablefor receiving transdermal injections of fluid, wherein the pressurizedfluid reservoir is connected to the fill tube.
 11. The gastric bandingapparatus of claim 1, wherein the pressurized fluid reservoir is locatedon the gastric band.
 12. The gastric banding apparatus of claim 1,further including a measuring device for measuring fluid flow throughthe inlet valve.
 13. The gastric banding apparatus of claim 12, furtherincluding a measuring device for measuring fluid flow through the outletvalve.
 14. A passively pressurized inflatable gastric banding apparatusfor treatment of obesity in a patient, comprising: a laparoscopicallyimplantable gastric band having an inflatable member for adjusting aninner circumference of the band, the pressure within the inflatablemember being denoted P2; a pressurized fluid reservoir connected toprovide fluid to inflate the inflation member, the pressurized fluidreservoir having a pressure P1; an inlet valve between the pressurizedfluid reservoir and the inflatable member; a controller remotelycontrollable from outside of the patient for actuating the inlet valveand passively increasing the fluid volume in the inflatable member whenP1>P2, thereby reducing the inner circumference of the band.
 15. Thegastric banding apparatus of claim 14, further comprising: an outletthat is not the pressurized fluid reservoir having a pressure P3; anoutlet valve between the inflatable member and the outlet; and whereinthe controller actuates the outlet valve and passively decreases thefluid volume in the inflatable member when P2>P3, thereby enlarging theinner circumference of the band.
 16. The gastric banding apparatus ofclaim 15, wherein the outlet is adapted to be in fluid communicationwith the peritoneal cavity of the patient.
 17. The gastric bandingapparatus of claim 15, wherein the outlet is a waste reservoir.
 18. Thegastric banding apparatus of claim 14, further including a fill tubeconnected to the inflatable member and a fill port on the end of thefill tube suitable for receiving transdermal injections of fluid,wherein the pressurized fluid reservoir is connected to the fill tube.19. The gastric banding apparatus of claim 14, wherein the pressurizedfluid reservoir is located on the gastric band.
 20. The gastric bandingapparatus of claim 14, further including a measuring device formeasuring fluid flow through the inlet valve.